Hydraulic pipe tong apparatus

ABSTRACT

Pipe gripping apparatus carried by a support frame including a hydraulic piston radially supported in fixed relation within the frame through a piston rod. A movable combination blind cylinder and pipe jaw is fitted around the piston for radial movement toward and away from gripping relation with pipe. The piston and cylinder defines a fluid pressure chamber connected to pressuring means for introducing fluid under pressure into the chamber to move the cylinder and pipe jaw into gripping engagement with pipe. A retraction arrangement is provided to move the cylinder and pipe jaw away from the pipe.

[ Mar. 12, 1974 3,420,148 l/l969 Doerfer et al. 3,548,692 112/1970Dickmann......

FOREIGN PATENTS OR APPLICATIONS 83l,292 3/1960 GreatBritain........................

Primary Examiner-Harold D. Whitehead Assistant Examiner--.l. T. ZatargaAttorney, Agent, or FirmWilliam S. McCurry; James M. Peppers [5 7]ABSTRACT Pipe gripping apparatus carried by a support frame in cluding ahydraulic piston radially supported in fixed relation within theframethrough a piston rod. A movable combination blind cylinder and pipejaw is fitted around the piston for radial movement toward and away fromgripping relation with pipe. The piston and lnventor:

Filed:

Appl. No'.:; 227,522

[51] Int.

Field of Search United States Patent [191 Carlberg [54] HYDRAULIC PIPETONG APPARATUS cylinder definesja fluid pressure chamber connected topressuring means for introducing fluid under pressure into the chamberto move the cylinder and pipe jaw into gripping engagement with pipe. Aretraction arrangement is provided to move the cylinder and pipe jawaway from the pipe.

XXNMXXXHR 75 575 52252 5 .l/ /.l./6/ /9UU9/92 96 696 62 262 2 H" 2Chapman............... Dickmann et al. O'Neill et al. McKibben et al.Wood Dinzl....... Stone................. Mitchell et iiliilliil.

6 Claims, 3 Drawing Figures Bill-.-

. HYDRAULIC PIPE TONG APPARATUS BACKGROUND or THE INVENTION The presentinvention relates to pipe tongs, and more particularly to an improvedhydraulic pipe gripping back-up tong adapted to be employed incombination with a power driven tong so that the parts of a well pipemay be connected or disconnected, the pipe gripping means of the back-uptong having application as well to other pipe tongs. The pipe grippingmeans employs a fixed piston unit cooperating with a movable combinationcylinder and jaw carrying unit equipped with pipe gripping jaws.

The present invention pertains to improvements in bacl -up tongs such asdisclosed in U.S. Pats. No. 3,246,547, No. 3,302,496 and No. 3,507,174,and which may be utilized with pipe handling apparatus such asdisclosedin U.S. PatsfNo. 3,505,913, No. 3,516,308 and No. 3,540,326,for example.

SUMMARY OF THE INVENTION The present invention provides pipe grippingapparatus wherein the pipe gripping forcemay be varied independently oftorqueapplied to connect or disconnect pIpe.

The presentinvention also provides pipe gripping apparatus of relativelysimple and inexpensive construction.

The present invention further provides pipe gripping apparatus whereinthe size and number of pipe gripping units employed in the apparatus maybe readily varied within specified dimensional limits to accommodatedifferent torque requirements.

The foregoing and other provisions and advantages reside in pipe tongapparatus of the present invention comprising a support frame having acenter adapted to receive pipe and pipe gripping means carried by thesupport frame including a hydraulic piston disposed radially toward saidcenter and supported in fixed relation within the frame through a pistonrod. A movable combinationcylinder and pipe jaw is fitted around thepiston for radial movement toward and away from gripping relation withthe pipe. The piston and cylinder defines a fluid pressure chambercommunicating with pressuring means for introducing fluid under pressureinto saidchamber to move said cylinder and pipe jaw into grippingengagement with said pipe. Retraction means is provided to move thecylinder and pipe jaw away from the pipe.

BRIEF DESCRIPTION OF THE DRAWING DESCRIPTION or THE PREFERRED EMBODIMENTI Referring first to FIG. 1, there is generally illustrated a back-uptong assembly and a power tong assembly 12 adapted to be supported abovethe floor (not shown) of the usual well drilling unit mounted above awell bore. Pipe, such as drill pipe or casing, is adapted to be run intoand pulled from the well bore. Such a pipe is illustrated in FIG. 1 asincluding an upper stand of pipe 14 in the illustrative form of a standof drill pipe having a tool joint pin end 18 thereon adapted to bethreadedly connected by the tong 12 to the box end 20 of a length orstand of the pipe 16 disposed in the well bore. In order to support thetong assembly 12 in an operative position above the well bore so thatthe stand of pipe 14 may be lowered therethrough for engagement with thepipe 16, a suitable crane 22 is provided, including a boom 24 projectingfrom a vertically disposed post 26. A cable 28 extends over sheaves 30and is connected to a pressure operated cylinder mechanism 32 disposedwithin the post 26, whereby the tong assembly 12 may be raised andlowered relative to the post 26 and thereby relative to the well boreinto which or from which pipe is being removed. Also forming a part ofthe crane 22 is a counterweight 34 slidable vertically along the post26, there being a second cable 36 also connected to the upper end ofcylinder 32, extending over a sheave 38, and connected also to thecounterweight 34 so that the mass of the tong assembly may be properlysupported. This crane assembly may be of any desired type such as hereinshown and in accordance with the disclosure in U.S. letters Pat; No.3,505,913, for example. Y

The tong assembly, as is typical of tongs of the type here involved,includes a head section generally denoted at 40 and a supporting andpower transmission section generally denoted at 42. The powertransmission section in the illustrative embodiment has a hydraulicmotor 44 adapted to be connected to a suitable source of motive fluidunder pressure (not shown) so as to drive the transmission mechanism ofthe tong assembly, which may be of any desired type, but which may beconstructed in accordance with the disclosure in the U.S. letters Pat.No; 3,516,308, for example. The head section 40 of the tong assembly 12may be of any desired type of tong head mechanism adapted to grip andeffect rotation of the pin end 18 of the pipe while the box end 20 ofthe pipe 16 is held against rotation either in the usual rotary tableslips or by the back-up tong assembly generally denoted at 10, made inaccordance with the invention and hereinafter to be more fullydescribed. The tong head 40 may be made in ac- I back-up tong 10 tendingto cause angular movement of the support structure 46, as an indicationof the connecting torque applied to pipe joints held by the backup tong,by rotation of the power tong assembly 12.

At the forward end of the support structure 46 is a back-up tong headassembly generally denoted at 54, I

the support structure 46 including brackets 56 connected to ears 58formed as part of the head assembly 54 by bolts 60. This head end of theback-up tong asof ears 62 projecting from the sides of the tong assembly12 and supporting bolts 64 which extend through outwardly extendedgussets 66 carried by the suport structure. Coiled springs 68 areprovided between the gussets 66 and the ears 62, and the gussets 66 andthe bolts 64, to cushion relative vertical movement between the head 40of the power tong assembly 12 and the head 54 of the back-up tongassembly 10.

Referring more particularly to FIGS. 2 and 3, backup tong head assembly54 is seen to include hydraulic pipe gripping units 70, each having ajaw unit 72 disposed to converge toward a common point which ordinarilywould be the center of the pipe 16 when box end is moved into headassembly 54. Each jaw unit carries one or more mortise and tenon mountedpipe dies 73, as shown, for ready removal and replacement. In

the illustrated embodiment, three of such gripping units Each grippingunit 70 includes a cylinder guide 74 4 with the three provided cylinderguides being joined as by welding through gusset members 76 to form themain body or frame of head 54 as shown. The head assembly ears 58 aremounted from two of the gusset members 76 as shown to mount head 54 withsupport structure 46 as previously mentioned. It is to be noted thathead unit 54 may be of welded construction as shown or integrally formedas a casting or forging, depending on production and service factors.

As shown in FIG. 3, the cylinder guide 74 may be of generallyrectangular shape in section. Reciprocably mounted within cylinderguides 74 is a movable jaw carrying cylinder 78 which mounts the jawunit 72 through a mortise and tenon structure 80 including a lock screw82 as shown. Each jaw unit 72 includes one or more pipe gripping dies 73also mounted through a mortise and tenon arrangement as shown. Theexterior of cylinder 78 is of rectangular configuration to registerwithin guide 74 in a manner preventing rotation of the cylinder withinthe guide.

A cylindrical piston 84 is mounted and retained on the distal end of apiston rod 86 by means ofa snap ring 88 as shown and mounted within acylindrical blind bore 90 defined within cylinder 78. The blind end ofbore 90, the piston 84 and the piston rod 86 define a pressure chamber92 which is rendered fluid tight by a seal ring 94 mounted between thepiston rod and the piston and seal rings 96 mounted between the pistonand the cylindrical wall of bore 90 as shown.

The supporting end of piston rod 86 is joined by threaded connectionthrough a support member or plate 98 and retained by a threaded nut 100.Support member 98 is connected to cylinder guide 74 and head assembly 54by means of fasteners such as cap screws 102. As can be seen, the piston84 and piston rod 86 are fixed and immovable with respect to the headassembly 54.

A flanged bushing 104 is mounted within the bore 90 of cylinder 78 andabout piston rod 86 to align the piston and piston rod within thecylinder and also to retain the piston within the bore. The bushing 104is retained in position by means of fasteners such as cap screws 106extending through an outer flange of the bushing and into threadedconnction within the wall of cylinder 78. A cylinder return spring 108is disposed around piston rod 86 and confined in compression between aflange formed within bushing 104 and the rear of piston 84 to urge thebushing 104 and attached cylinder 78 into retracted position againstsupport member 98.

' A passage 110 is longitudinally defined through piston rod 86 toprovide fluid communication through the piston rod into chamber 92.

When fluid under pressure, oil for example, is introduced throughpassage 110 into chamber 92, cylinder 78 and jaw unit 72 for each of thepipe gripping units is displaced inwardly to concurrently converge intogripping contact with pipe box end 20. The gripping force corresponds tothe fluid pressure introduced into chamber 92. In the embodiment ofFIGS. 2 and 3, the operating pressures may be in the range of 5002,500p.s.i. (35-175 kilograms/sq. centimeter for example.

When the pressure is released from chamber 92, theresilience of spring108 imposed against the bushing 104 displaces the fluid out of chamber92 through passage 1 l0 and returns cylinder 78 into retracted positionwith bushing 104 abutting support member 98. Thus, each cylinder 78 andjaw unit 72 is moved from retracted position to gripping posiiton andreturn by periodic admission of fluid under pressure into chamber 90.

A source of fluid under pressure 112 is connected through a manual orremotely operated switching valve 1 14 through conduits 116 and fluidfittings 118 into respective communication with each of passages 110.Valve 1 14 is also connected to a return sump as shown. With valve 114in a first position, fluid under pressure is admitted into each of thechambers 92, causing each of the cylinders 78 and jaw units 72 to extendand converge into gripping relation with pipe box end 20. When valve 114is switched to a second position the pressurized fluid is blocked offand the fluid in chambers 92 is free to flow into the return sump. Thusperiodic switching of valve 114 causes periodic gripping and release ofpipe gripping units 70 as desired.

In operation of the back-up tong assembly 10 in combination with a powertong assembly 12, the assembly 12 will be operated to grip and rotate ajoint of pipe in either a righthand or lefthand direction respectively,when a pipe joint is to be connected or disconnected. During the initialor final stages of rotation, as applicable, the back-up tong unit mayremain idle. However, when the tool joints l8 and 20 shoulder together,as when connecting, or need to be broken apart as when disconnecting,the back-up tong unit 10 is employed to apply high torque resistantforces to the tool joint box end 20 in either direction, as necessary,while torque is applied to pipe pin end 18 by power tong 12.

Following the above described jaw engaging operations, the back-up jawunits 72 will remain retracted in response to the springs 108.

The foregoing description and drawing will suggest other embodiments andvariations to those skilled in the art, all of which are intended to beincluded in the spirit of the invention as herein set forth.

That being claimed is:

1. Pipe tong apparatus comprising a horizontal support frame providing acentral opening adapted to receive a vertically disposed length of pipe;pipe gripping means carried by said support frame, said pipe grippingmeans including a plurality of horizontally and radially disposed pipegripping units arcuately arranged about said central opening, each ofsaid pipe gripping units having a cylinder guide carried by said supportframe within said cylinder, a piston rod having one end fixed to saidpiston and the other end fixed to said frame, said piston and saidcylinder defining a fluid pressure chamber at said blind end of saidcylinder, fluid pressure manifold means for simultaneously introducingfluid under pressure into the fluid pressure chambers of all of saidpipe gripping units to slide their respective cylinders towards a pipedisposed in said central opening, thereby to move their respective jawmeans into gripping engagement with the pipe, and retraction meansassociated with each of said units for sliding their respectivecylinders away from the pipe, thereby to move their respective jaw meansout of engagement with the pipe.

2. The apparatus of claim 1 wherein said retraction means comprises acoil spring mounted in compression between the rear of said piston andthe rear of said cylinder.

3. The apparatus of claim 1, wherein said manifold means includes afluid passage defined through said piston rod to the exterior of saidframe.

4. The apparatus of claim 3 including a fluid switching valve connectedthrough conduit means and said passage into communication with saidchamber and adapted for connection with a fluid pressure source toswitch fluid under pressure into and out of said chamber.

5. The apparatus of claim 1 wherein said support frame includes gussetmeans connecting said pipe gripping units together.

6. The apparatus of claim 1 wherein said jaw means is removable fromsaid cylinder and at least one pipe die is removably mounted in said jawmeans.

1. Pipe tong apparatus comprising a horizontal support frame providing acentral opening adapted to receive a vertically disposed length of pipe;pipe gripping means carried by said support frame, said pipe grippingmeans including a plurality of horizontally and radially disposed pipegripping units arcuately arranged about said central opening, each ofsaid pipe gripping units having a cylinder guide carried by said supportframe and providing a radially extending guideway therein, said guidewaybeing rectangular in cross-section normal to its radial dimension, ablind cylinder disposed in said guideway and having a rectangularcross-section complemental to the cross-section of said guideway forpreventing rotation of said cylinder within said guideway, the blind endof said cylinder facing said central opening, pipe engaging jaw meansmounted on said blind end, said cylinder being slidable in said guidewayto move said jaw means into and out of engagement with a length of pipein said opening, a piston fitted within said cylinder, a piston rodhaving one end fixed to said piston and the other end fixed to saidframe, said piston and said cylinder defining a fluid pressure chamberat said blind end of said cylinder, fluid pressure manifOld means forsimultaneously introducing fluid under pressure into the fluid pressurechambers of all of said pipe gripping units to slide their respectivecylinders towards a pipe disposed in said central opening, thereby tomove their respective jaw means into gripping engagement with the pipe,and retraction means associated with each of said units for slidingtheir respective cylinders away from the pipe, thereby to move theirrespective jaw means out of engagement with the pipe.
 2. The apparatusof claim 1 wherein said retraction means comprises a coil spring mountedin compression between the rear of said piston and the rear of saidcylinder.
 3. The apparatus of claim 1, wherein said manifold meansincludes a fluid passage defined through said piston rod to the exteriorof said frame.
 4. The apparatus of claim 3 including a fluid switchingvalve connected through conduit means and said passage intocommunication with said chamber and adapted for connection with a fluidpressure source to switch fluid under pressure into and out of saidchamber.
 5. The apparatus of claim 1 wherein said support frame includesgusset means connecting said pipe gripping units together.
 6. Theapparatus of claim 1 wherein said jaw means is removable from saidcylinder and at least one pipe die is removably mounted in said jawmeans.